Here are the key habits Longo recommends to his patients for staying healthy and living long, and that he also practices in his own life.

“I’d like to make it to 120. But whatever I get, it’s okay. At least I’ll have no regrets saying, ‘Well, I didn’t do all the right things.'”

“I do everything that I preach. I don’t know if I [hit the target] all the way, but I certainly think it’s good to try,” Longo told CNBC Make It in 2024.

Longo is the director of the Longevity and Cancer Laboratory at the IFOM Institute of Molecular Oncology in Milan, Italy. He is also the director of the Longevity Institute of the Leonard Davis School of Gerontology at the University of Southern California-Los Angeles.

Since 1989, Valter Longo has dedicated his research to understanding the factors that contribute to overall health and longevity. About 20 years ago, Longo returned to Italy where he grew up, seeking to better study the practices that have helped regions like Sardinia become home to some of the world’s longest-living people.

1. Eat mostly plant-based foods

“I recommend what I call the longevity diet, which takes from lots of different things,” Longo says. “Both the Okinawa diet and the Mediterranean diet.”

To follow Longo’s longevity diet, you should aim to eat in a way that aligns with these guidelines:

Mainly vegan

High vegetable intake, and a relatively low fruit intake

Tree nuts

Legumes

Whole grains

Fish three to four times a week

If you’re between the ages of 20 and 70, he suggests eating “no red meat, no white meat, maybe two, three eggs a week, at most, very little cheese [and] very little animal-based products.”

Studies show that eating in accordance with the Mediterranean diet (or as close to it as possible) may lower your likelihood of developing health conditions like Type 2 diabetes and heart disease.

2. Fast for 12 hours a day

“I recommended 12 hours of fasting daily. Let’s say you eat between 8 a.m. and 8 p.m. or 7 a.m. and 7 p.m.,” Longo says.

He also adheres to the fasting-mimicking diet, which was created by researchers, including Longo, at UCLA. The diet entails eating foods “high in unsaturated fats and low in overall calories, protein, and carbohydrates, and is designed to mimic the effects of a water-only fast while still providing necessary nutrients,” according to the USC Leonard Davis School of Gerontology.

After fasting for five days, you should return to your normal diet for the rest of the month. The researchers tested the effects of the diet on participants who followed the fasting-mimicking diet every three to four months.

A 2024 study found an association between the fasting mimicking diet and a lower risk of cancer, heart conditions and diabetes in mice. Longo was the leading author of the paper.

3. Get 150 minutes of exercise a week, and walk often

Exercising for at least 150 minutes a week (2 hours and 30 minutes) can have a positive impact on your overall health, Longo says. This aligns with the U.S. Department of Health and Human Services’ 2018 physical activity guidelines.

Having at least 50 minutes of that physical activity be strenuous exercise that challenges you, can lead to even more health benefits, he adds. Vigorous physical exercise includes running, jogging or going to a fitness class, according to HHS.

“On top of that, I add an hour a day of walking. Going up and down stairs. Be active in addition to the 150 minutes,” Longo says.

“If you’re going to the store, and the store is not too far away, walk. Some of these things have been abandoned, but they were very normal for the people that made it to 100 years of age.”

4. Prioritize good sleep and positive mental health

“It’s very important to sleep well,” Longo says. Though he notes sleep medicine is not his area of expertise, he highlighted the importance of getting adequate sleep for overall wellness.

Some practices sleep experts recommend for a good night’s rest include:

Sticking to the same sleep time and wake time

Developing a bedtime routine that helps your body wind down

Scheduling naps before 2 p.m., and limit them to between 20 and 30 minutes long (if you enjoy napping)

Keeping your bedroom between 60 and 68 degrees at night

Maintaining positive mental health is vital for longevity, too, Longo says. To stay positive, happiness expert Arthur C. Brooks suggests treating your happiness like an investment portfolio by prioritizing four areas: faith, family, friends and meaningful work.

“None of these things can make up happiness all on their own,” Brooks said during his Harvard happiness course online. “They complement each other and exist in harmony.”

Want to be a successful, confident communicator? Take CNBC’s online course Become an Effective Communicator: Master Public Speaking. We’ll teach you how to speak clearly and confidently, calm your nerves, what to say and not say, and body language techniques to make a great first impression. Get started today.

Plus, sign up for CNBC Make It’s newsletter to get tips and tricks for success at work, with money and in life, and request to join our exclusive community on LinkedIn to connect with experts and peers.